Abstract：The mechanical behavior of reinforced concrete crane girder bolted to rock wall of chamber is analyzed with nonlinear finite element method. The concrete and rock mass are modeled by Drucker-Prager elasto-perfectly plastic constitutive relation. The Drocker-Prager yield criterion has found wide practical application as a method of defining the stress conditions under which rock mass will deform inelastically and collapse. Combined with the extending project practice of underground powerhouse at hydropower stations，the fracturing mechanism and stability of crane girder are investigated numerically. Computational results show that the cohesion and friction angle between rock mass and concrete have a notable influence on the stability of crane girder bolted to rock wall of chamber. The safety factor of concrete crane girder will be reduced with the decrement of inner cohesion between the rock mass and concrete crane girder. The safety factor of concrete crane girder can exceed 3.7 while the failure of interface between the rock mass and concrete occures. The further excavation of underground powerhouse will affect the stress distribution of system bolts and rock mass near crane girder. It is very important for improving stress states and enhancing stability of concrete crane girder to control effectively rock damages induced by excavation blasting.
